It has been known that when producing polyurethane resin, use of polyisocyanate derived from hexamethylenediisocyanate allows for production of polyurethane resin with excellent weatherability.
For such polyisocyanate, for example, Patent Document 1 has proposed a polyisocyanate composition derived from a hexamethylenediisocyanate monomer and isobutanol, having an isocyanurate trimer concentration of 60 mass % under conditions where hexamethylenediisocyanate monomer and a solvent are not included, having 1% or more and less than 5% of a ratio of the number of the allophanate group/isocyanurate group derived from isobutanol, having a uretdione dimer concentration of 12 mass %, and having a viscosity at 25° C. of 620 mPa·s (for example, see Example 1).